1 / 22

Influence of a Magnetic Field on the Electrodeposition of Nickel-Iron Alloys

SFB 609. Influence of a Magnetic Field on the Electrodeposition of Nickel-Iron Alloys. Adriana Ispas , Andreas Bund. Outline. Introduction Experimental details Results and discussions Iron content vs. current density Iron content vs. magnetic field Hydrogen evolution

adem
Download Presentation

Influence of a Magnetic Field on the Electrodeposition of Nickel-Iron Alloys

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SFB 609 Influence of a Magnetic Field on the Electrodeposition of Nickel-Iron Alloys Adriana Ispas, Andreas Bund

  2. Outline • Introduction • Experimental details • Results and discussions • Iron content vs. current density • Iron content vs. magnetic field • Hydrogen evolution • Morphology aspects

  3. Alloy Deposition:isthe simultaneous deposition of more than one metal Advantages: • Most of the alloys can be deposited without much difficulties • Most of the alloys have useful properties: finer grains, harder, stronger, more corrosion resistant than the parent metals, high magnetic permeability → Because of that, in some applications the alloys replace the single metal Disadvantage: • Alloys deposition request close control of the electrolytic bath • Ni-Fe alloys present a high internal strength, hardness and special magnetic properties Brenner: „Anomalous codeposition“ is characterized by the anomaly that the less noble metal deposits preferentially Abner Brenner, Electrodeposition of Alloys. Principle and Practice, Vol.1 (1963), Academic Press New York and London, p.77 “Modern Electroplating”, fourth edition, edited by M. Schlesinger and M. Paunovic, John Wiley & Sons, INC., 2000, p. 468

  4. Magnetic field influences • the properties of the deposited layers • the transport of electroactive species (MHD effect) Force acting on the moving ions in the solution (Lorentz force): q= electric charge E=electric field v= velocity B= magnetic field Force due to B Gradient Paramagnetic force: m -the molar susceptibility C –concentration  -the vacuum permeability

  5. Disk electrode ΔV Magnetic field effects • induces an additional convection in the electrolyte that decreases the thickness of the diffusion layer → increasing of the limiting current • increases the mass transport From: J. M. D. Coey, G. Hinds, Journal of Alloys and Compounds, 326(2001), 238-245.

  6. Orientation 1 Orientation 2 Experimental set-up RE CE C Q S N WE L NA Experimental details Composition of the bath: 0.5 M NiSO4*6H2O; 0.01 M FeSO4*7H2O; 0.4 M H3BO3 ; pH=2-3 0.5 M NiSO4*6H2O; 0.07 M FeSO4*7H20; 0.4 M H3BO3; pH=2 N, S → poles of the electromagnet C → electrochemical cell Q → quartz WE → working electrode (Au) CE → counter electrode (Pt) RE → reference electrode (Ag/AgCl/KCl) NA → Network Analyzer

  7. film gold electrodes Damping Mass shear motion quartz Quartz Crystal Microbalance Sauerbreyequation: Complex frequency shift (μq = shear modulus [g/cm s2]; ρq = density of the quartz [g/cm3]; A =piezoelectrically active area)

  8. Phase Diagram From: Scientific Group Thermodata Europe Binary Phase Diagram Collection

  9. Saturation flux density values From: E.I. Cooper et al. , IBM J. Res. & Dev., vol. 49 (2005), no. 1, 103-126.

  10. Iron content in Weight percent 1-st Electrolyte Composition of the bath: 0.5 M NiSO4*6H2O; 0.01 M FeSO4*7H2O; 0.4 M H3BO3 ; pH=2-3

  11. Influence of the B field on iron content B || E B  E

  12. The damping change of the quartz

  13. Morphology aspects i= -25mA cm-2; B=0mT; pH=3 i= -25mA cm-2; B=740mT, ; pH=3

  14. i= -50mA cm-2; B=0 mT; pH=2 i= -50mA cm-2; B=445mT, ||; pH=2 i= -50mA cm-2; B=740mT, ; pH=2

  15. Itotal= -35 mA cm-2 B = 445 mT, B||E B = 530 mT, BE B = 0 mT • Rq is the standard deviation of the Z values within the given area, calculated from the topography image (the height), • Zi is the current Z value, • Zave- the average of Z values within the given area • N- number of points from the given area.

  16. Iron content in Weight percent 2-nd Electrolyte Composition of the bath: 0.5 M NiSO4*6H2O; 0.07 M FeSO4*7H20; 0.4 M H3BO3; pH=2

  17. Influence of the B field on iron content

  18. Partial current of Hydrogen evolution

  19. Roughness of the deposit

  20. Morphology aspects Itotal= -50 mA cm-2 B=528 mT, BE B=0 mT B=406 mT, B||E

  21. Conclusions • Fe content is changing with the B field in an opposite way for the two electrolytes investigated • Fe content of the permalloy increases for (B  E) and is almost constant for (B || E) • Roughness and hydrogen evolution are not influenced in the case that B is parallel to E • Specific morphology is generated in the presence of a B field

  22. Thank you!

More Related